Really only need the password to extract the uImage.img as ther rest of the data is not required.

Steps

Partition the drive

Starting with just one disk, partition the drive, using GPT partition schema, as follows:

sda1 1GB (ext3) /boot

sda2 1GB (swap)

sda3 10GB (ext3) /

remainder of the disk is arbitrary (ext3)

Population of boot partition

Create initrd.buffalo

Take care the setup the linuxrc script correctly so that the correct partition is used during the boot process.

Copy uImage.buffalo and initrd.buffalo

Copy the following files into the boot partition (/dev/sda1). that is all that is required in the /boot partition. It should be possible to make it very small.

Population of the root partition

Untar the Debian filesystem into sda3. Be sure to use the numeric-owner switch. Confirm that /lib/modules is correct, that the network is setup correctly (/etc/network/interfaces) and that /etc/fstab has the correct partitions setup.

Outcome

This should leave you with a GPT partitioned drive with stock uImage (kernel) and a custom initrd in the boot partition (to be mounted at /boot) and a custom armel Debian filesystem in the root partition (to be mounted at /).